This short film stars Laurent Fresnais as the Wanderer and is a graduation project from Isart Digital.
The Wanderer makes for an interesting NPC in any sort of tabletop RPG. He’d make dramatic changes to the world, and your PCs might not know how to react. It might depend on whether the Wanderer stayed to ruined and uninhabited places or not.
Alternatively, the Wanderer’s mission might become your player characters’ mission. Rather than roam the land, dealing death as they go, the PCs become literal bringers of life.